Locking nut



FIG. 1 is a perspective view;

FIG. 2 is another perspective view;

FIG. 3 is another perspective view;

FIG. 4 is another perspective view;

FIG. 5 is another perspective view;

FIG. 6 is a front view;

FIG. 7 is a back view;

FIG. 8 is a top view;

FIG. 9 is a bottom view;

FIG. 10 is a right side view; and,

FIG. 11 is a left side view.

The broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design. 

CLAIM The ornamental design for a locking nut, as shown and described. 